Galileo

Motion was first understood by Galileo in the 17th
century.

Galileo made careful experiments and compared his predictions
to those experiments. He invented or greatly refined water clocks
to make the time measurements he needed. In understanding motion
-- esp'ly free fall -- Galileo observed balls rolling down
inclined planes. As the planes became steeper and steeper, his
results more closely approached those of free fall.

Galileo may be called the Father of Modern Science
because of his emphasis on experimental results. The correctness
of a scientific theory must be based upon the agreement of its
predictions with experimental results.